1. Field of the Invention
This invention relates to semiconductor packaging technology, and more particularly, to a semiconductor package module used to pack a semiconductor chip of an optically-sensitive type, such as an image-sensor chip or an ultraviolet-sensitive EP-ROM chip.
2. Description of Related Art
Semiconductor packaging technology is used to pack one or more semiconductor chips in a single module. Typically, the semiconductor chip or chips are enclosed inside an opaque encapsulating body, and thus is invisible from the outside. However, for optically-sensitive types of semiconductor chips, such as image-sensor chips or ultraviolet-sensitive EP-ROM (Electrically-Programmable Read-Only Memory) chips, it is required to allow these chips to be optically sensitive to outside light. For this reason, a special semiconductor package configuration is used to pack these types of semiconductor chips. One conventional package configuration to pack an optically-sensitive semiconductor chip is to mount it inside a centrally-hollowed encapsulation body and then, after performing wire bonding to the chip, hermetically seal an transparent lid over the opening of the centrally-hollowed portion of the encapsulation body.
One drawback to the forgoing package configuration, however, is that, during the manufacture thereof, resin flash on lead frame is a serious problem, which would undesirably degrade the quality of the die bonding and wire bonding on the flashed parts of the lead frame. To solve this problem, various solutions have been proposed, including, for example, the U.S. Pat. No. 5,070,041 entitled xe2x80x9cMETHOD OF REMOVING FLASH FROM A SEMICONDUCTOR LEADFRAME USING COATED LEADFRAME AND SOLVENTxe2x80x9d, which can remove resin flash built up on lead frame without damaging resin molded section. This patented method is characterized in the steps of coating an organic high-molecule substance over the areas of the lead frame that are to be unencapsulated by the encapsulation body, and then, after the encapsulation body is completely formed, using a solvent to remove the organic high-molecule coating, whereby the resin flash over the organic high-molecule coating can be together removed. After this, a semiconductor chip is mounted onto the flash-free die pad, and a lid is then covered to the opening of the centrally-hollowed portion of the encapsulation body.
The forgoing patented method, however, has the following two drawbacks. Firstly, the step of coating organic high-molecule substance and the subsequent step of dissolving the coating to remove resin flash are quite complex in procedure and costly to implement, making the overall manufacture process quite cost-ineffective. Secondly, the solvent being used would cause pollution and is thus environmentally-unfriendly to use.
It is therefore an objective of this invention to provide a new semiconductor package configuration for optically-sensitive semiconductor chips, which can help prevent resin flash on lead frame during the manufacture thereof.
It is another objective of this invention to provide a new semiconductor package configuration for optically-sensitive semiconductor chips, which is more simplified in procedure and more cost-effective to implement than the prior art.
It is still another objective of this invention to provide a new semiconductor package configuration for optically-sensitive semiconductor chips, which can be manufactured without having to use environmentally-unfriendly solvent that would cause pollution to the environment.
In accordance with the foregoing and other objectives, the invention proposes a new semiconductor package configuration for optically-sensitive semiconductor chips.